Mycogeography

Imports,
exports and puzzles

Since the beginning of human migration, people will have been transporting
organisms from one place to another. Sometimes this was done intentionally,
at other times by accident. Before the advent of stricter quarantine laws, Europeans
have intentionally brought numerous plants and animals into Australia. Simultaneously
they have unintentionally brought various fungi into the country. Of course,
numerous products have been shipped out of Australia - and with them have gone
some fungi as well. In this section there'll be some examples of this unconscious
"trade" in fungi. The section will finish with some puzzles - distributions
for which there are not yet any convincing explanations.

Introduced by humans

While Australia now has strict quarantine laws to stop the unplanned
introduction of overseas organisms, the earlier years of European settlement
saw numerous foreign species introduced to the country. At one time such introductions
were highly organised and carried out under the auspices of the Acclimatisation
Societies of the various states, when they were separate colonies. The aims
of such societies were to introduce both agriculturally useful animals and plants
as well as to "beautify" Australia through the introduction of foreign
animals and plants. Even after the peak of Acclimatisation Society activity,
there were still many smaller scale introductions. Understandably, if you import
animals or potted plants you will bring in the spores and micro-organisms in
animal guts as well as the mycelia that are growing with those pot plants.

Amanita muscaria

Melanogaster sp.

As a result a number of fungi have been accidentally introduced into Australia.
Quite a few mycorrhizal species have come in. To give a few examples, we have
Amanita muscaria, Amanita phalloides,
Hebeloma crustuliniforme ,
Lactarius deliciosus, Paxillus involutus, Tricholoma terreum,
amongst the mushrooms; Leccinum scabrum and several Suillus
species in the boletes; the truffle-like species of Rhizopogon
and Melanogaster. The species involved are well-known to be mycorrhizal
with various northern hemisphere trees and in Australia they are almost always
found associated with the same, introduced trees and this is very good evidence
that these have been introduced. It is most likely that Amanita phalloides
(the Deathcap) (SEE DEATHCAP SECTION)
came into Australia with imported oak trees.

Robert Brown reported Amanita
muscaria to be in Australia, in his 1814 botanical appendix to Matthew Flinders'
account of the Investigator voyage. However, this record demands a good
helping of the healthy scepticism referred to earlier. Brown had left Australia
in 1805 and collected no specimen in support of his claim, nor recorded it for
any particular location in his diary. In fact no Amanita muscaria specimens
are known from Australia until much later and it is possible that Brown mistook
the native Amanita xanthocephala
for Amanita muscaria. The two are quite different and, really, should
never be confused. However, there is a specimen of the former, originally named
as the latter, in the Melbourne herbarium - which lends support to the idea
of mistaken identity. Moreover, Brown was not a mycologist and may have happily
applied a European name after the most fleeting of glances at the Australian
specimen.

In Australia Amanita muscaria is most commonly found in pine plantations,
but it has also been found in Tasmanian Nothofagus forest, showing that
it has adapted to a new mycorrhizal partner. A number of introduced animals
and plants have become serious ecological or economic pests. Think of the rabbit
and blackberry. Have any of these introduced fungi become problems? At present
we don't know, but when a species such as Amanita muscaria is found in
native Nothofagus forests you might wonder if it is displacing some native
mycorrhizal species.

Exported by humans

Aseroe rubra

Anthurus archeri

On the other hand, a few Australian fungi have found their way overseas. In
1829 the stinkhorn Aseroe rubra, the first Australian fungus to be named
(by Labillardiere in 1800),
was found growing in a glasshouse at the Royal Botanic Gardens in London, on
soil imported from Australia. Well over a century later, in 1993 it was found
about 16 kilometres away from the botanic gardens and this was the first outdoor
find of the species in Europe. Another Australian stinkhorn, Anthurus archeri,
has also made its way to Europe and appears to have been carried there either
through the wool trade or by Australian soldiers who fought in France during
the First World War.

Hydnangium carneum
is one of the many Australian truffle-like fungi. It is quite common and widespread
in Australia and also in many other parts of the world. One writer commented
that it appears to have gone wherever Eucalypts have gone. Interestingly enough,
while a good Australian species, the original description (published in 1839)
was based on a specimen collected in the botanic gardens at Grunewald, near
Berlin in Germany. You would not find it too surprising to find that it has
travelled to many of the major parks in continental Europe, Great Britain and
North America. After all, during the 19th or early 20th centuries many eucalypts
will have been imported by various botanic gardens and private plant collectors
in those countries. However, Hydnangium carneum has also turned up in
places you may initially find surprising, such as the Inner Hebrides and the
Falkland Islands.

Laccocephalum mylittae, left and above.

The sclerotium-forming polypore Laccocephalum mylittae, previously known
as Polyporus mylittae, has turned up once in New Zealand - seemingly
on a railway sleeper imported from Australia. There is also some evidence that
Amanita muscaria (introduced to Australia, from Europe) then moved to
South America from an Australian source. It may also be that the relatively
recent New Zealand occurrences of Jafneadelphus ferrugineus
and Mycena viscidocruenta
are due to accidental introduction by humans.

Puzzling distributions

Then there are oddities such as Hypholoma tuberosum. Numerous specimens
of this mushroom were found in Vancouver, Canada over several years from 1982.
They would appear in compost beds and mulch piles in cultivated parks or gardens
and commonly grew out of sclerotia, which could be several centimetres in diameter.
It became obvious that this was a new species and a formal description was published
in 1988, when it was still known only from Vancouver. The
authors commented that given no records before 1982 and the only known occurrences
being in urban parks or gardens, the fungus was likely to be an introduced species.

Hypholoma tuberosum

In 1987 fungal sclerotia and fruiting bodies were found in Australia, with
potted trees used as ornamental plants in commercial buildings in Sydney. After
the appearance of the Canadian paper it became clear that the Sydney specimens
were examples of the same species. The potting mixes contained coarse pieces
of peat. Later in the same year, fruiting bodies were collected from the drier
areas of Wingecarribee
Swamp, between the towns of Moss Vale and Roberston in NSW. At that time
commercial peat mining was carried out at the swamp. In 1990 numerous fruiting
bodies were found in the sandy margins of a creek in Sydney, in the vicinity
of numerous commercial nurseries. In 1995 numerous fruiting bodies and sclerotia
were found in a retail plant nursery in Canberra, in a coarse peat/sand mix
used to hold tree ferns awaiting sale. The nursery owner did not know the source
of the peat used in that holding bed.

The fungus does not appear to be harmful to cultivated plants, nor is there
any suggestion it is mycorrhizal. In the intervening years the fungus has not
been found anywhere else. The question of its true home and natural range is
still unanswered. The Canberra and Sydney occurrences are undoubtedly introductions
via peat - but Australian or overseas peat? For many years peat was imported
to Australia from Europe and New Zealand, but the species has not been found
in those regions. The only natural habitat so far known is the Wingecarribee
Swamp, so perhaps that's the home of the species and it was introduced to Vancouver
from Australia - but
investigations have shown no connection between Australia and Vancouver in the
trade of peat or potted plants.

Crepidotus improvisus is a small, stemless mushroom with the semi-circular
caps up to 2 centimetres across, attached directly to rotting wood by their
flat edges. The species is known from NSW, Papua New Guinea, New Zealand, Chile
- and Poland. Excluding Poland, the other countries constitute a Gondwanan spread.
Is the Polish record correct? The Polish specimen has been examined by a competent
mycologist - so there are very good reasons for accepting the identification.
Perhaps the species is of Gondwanan origin and after the collision of Australasia
with Asia moved north to what is now Europe. But then, why are there no records
of the species between Papua New Guinea and Poland? That's a large intermediate
area and surely a Gondwanan species migrating into Eurasia should have been
found somewhere else in that large area. It may very well have been collected
elsewhere in Eurasia and stored in some herbarium, but mis-identified. Or perhaps
the species been accidentally introduced to Poland in modern times, rather than
getting there at the end of a long overland migration from Gondwana.

The first account of the polypore Laccocephalum hartmanni was published
in 1883 by the English mycologist M.C. Cooke, on the basis of a specimen found
in Australia. He used the name Polyporus hartmanni and it was known by
that name for many years. For over a century this species was known only from
Australia but a paper in 1995 reported the first non-Australian record, from
Japan. Interestingly, it turned out that a specimen collected in Japan in 1931
was an example of this species.